JP2545310B2 - Connection structure of underground continuous wall - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for connecting an underground continuous wall with a horizontal reinforcing bar joint.

[0002]

2. Description of the Related Art As is well known, a continuous underground wall is formed with a horizontally long excavation hole in the ground, and a reinforcing bar cage is inserted into the excavation hole.
Next, concrete is poured into the excavation hole to fabricate a reinforced concrete panel in the ground, and the concrete panel is used as a unit element and sequentially connected. Conventionally, when an underground continuous wall is used as an earthquake-resistant wall on an underground floor, the panels are connected to each other by a crossbar joint method for transmitting an in-plane force.

Further, as a joint construction method, a horizontal braided joint construction method may be adopted as a wall-to-wall joint construction method capable of transmitting in-plane and out-of-plane forces. This construction method is shown in FIGS. 5 and 6. In the preceding element 1, the reinforcing bar joint 5 is projected from the partition plate 3 of the reinforcing bar basket 4 in which the partition plate 3 as the iron plate form is incorporated at the rear end. . This rebar joint 5 is also a rebar basket 4
Similarly, the horizontal streaks 5a and the vertical streaks 5b are combined.
The concrete placed on the side of the preceding element 1 is stopped by this partition plate 3. The following element 2 has a rebar cage 9 provided with a rebar joint 8 at the tip. The reinforcing bar joint 8 is narrow so as to fit inside the reinforcing bar joint 5 and is composed of a combination of horizontal bars 8a and vertical bars 8b as in the reinforcing bar joint 5, but the horizontal bars 8a are bent and their It is configured to narrow the gap.

After the concrete 6 of the preceding element 1 is poured, the reinforcing bar basket 9 of the trailing element 2 is arranged in the excavation hole 10, and although not shown, the concrete of the trailing element 2 is poured. The reinforced rebar joint 5 and the rebar joint 8 are wrapped to make a joint.

[0005]

In the conventional joint joining structure shown in FIGS. 5 and 6, the horizontal bars 5a and 8a, which are cutting rebars, are lapped at intervals with respect to each other to join the reinforcing bar joints. Therefore, when an out-of-plane bending stress β is applied, these horizontal streaks on the pulling side bounce outward, and as shown by α in Fig. 5, cracks occur in the concrete on the trailing element 2 side and the yield strength decreases. There is a risk that

[0006] Splitting and breaking by such horizontal streaks 5a and 8a is extremely fragile, and splitting and breaking cannot be prevented even if the amount of horizontal streaks is increased. In addition, the splitting fracture resistance is positively correlated with the overlapping length of the horizontal streaks, and even if the leading panel side horizontal line and the trailing panel side horizontal line are vertically separated, the splitting fracture strength is somewhat higher. Split fracture occurs at.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, to reliably transmit the yield strength of the horizontal streak to prevent split fracture, and to adjust the position of the joint portion. Another object of the present invention is to provide a joint structure for an underground continuous wall in which the effect of preventing split fracture is further improved by restraining the joint portion of the joint from the outside and suppressing the joint portion from the outside.

[0008]

In order to achieve the above object, the present invention provides a partition plate at the reinforcing bar basket end of the preceding element, and a joint projecting from this partition plate and a joint at the reinforcing bar basket end of the trailing element. In the joint structure of the underground continuous wall connecting the horizontal streaks with each other, the partition plate has an H-shaped cross section such that the flange plate acts to restrain the connecting portion of the both joints to the outside, and The joint is a rectangle with a horizontally long cross-section that leaves enough space to adjust the front and back when the enlarged tip of the other joint is inserted inside, and the vertical direction with vertical slits formed on the side surface on the short side. A box-shaped hollow body continuous with is arranged on the side of the trailing element with respect to the partition plate, and the side face opposite to the vertical slit is provided so as to connect the horizontal streaks spaced in the upper and lower stages,
The other joint is composed of a locking member having a square or flat bulging tip formed at the tip and connected to horizontal stripes at the rear end with vertical intervals, and this locking member is provided with a vertical slit in the gap. Insert through, by filling the cement-based grout material before and after, to join in a state in which the axis of the horizontal bar of the reinforcing bar basket of the preceding element side and the horizontal bar of the reinforcing bar basket of the trailing element side match, or The gist of the enlarging tip of the locking member is to form a box that is continuous in the vertical direction, and use this box as a grout injection tube.

[0009]

According to the first aspect of the present invention, the joint is arranged on the extension line of the reinforcing bar basket on the trailing element side on the extension line of the horizontal bar of the reinforcing bar basket on the leading element side. As a result, the yield strengths of the horizontal muscles can be reliably transmitted by connecting the axes of the horizontal muscles to each other in an aligned state. Moreover, since the hollow body as a box joint of this joint is a rectangle with a laterally long cross section, there is room before and after the enlarging tip inserted into this hollow body, and it is possible to easily adjust the position here, especially, Reinforcing bar baskets of underground continuous walls usually have a width of 5 to 7 m and a height of 20 m in the direction in which the walls are continuous. It is difficult to hang them exactly at the planned place because they are hung by a crane and built. Therefore, it is important that the position of the joint can be adjusted.

Further, since the horizontal reinforcing bars are long in the reinforcing bar basket of the continuous underground wall, the horizontal reinforcing bars are arranged at a certain interval in the upper and lower steps over the height of the reinforcing bar basket. Since it is difficult to arrange them, if they are aligned by cutting etc., there is a possibility that the end of the reinforcing bar basket will have an error on the left and right, but even if there is such an error, the locking member is inserted by the void of the hollow body. be able to.

Moreover, since the joint portion of this box joint is located on the trailing element side, the joint of the horizontal reinforcing bar end of the reinforcing bar basket on the preceding element side is not solidified with concrete around it, so the direction of the joint, etc. Can be adjusted.

Further, the partition plate has an H-shaped cross section having flange plates at both ends, and this flange plate acts to restrain both joints from the outside, thereby enhancing the breaking fracture resistance. Can be planned.

According to the second aspect of the present invention, in addition to the above-mentioned function, the enlarging tip portion is constituted by a box which is continuous in the vertical direction, and the box is used as a grout injection pipe, whereby the grout in the hollow body is The injection work can be performed reliably and easily.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a first view of a joint structure of underground continuous walls of the present invention.
2 is a vertical sectional side view of the same, and the same components as those in FIGS. 5 and 6 showing the conventional example are designated by the same reference numerals.

On the side of the preceding element 1, a reinforcing bar cage 4 having a partition plate 3 as a steel plate form at the rear end is used, and a reinforcing bar cage 9 serving as a trailing element 2 is arranged behind the reinforcing bar cage 4. It is the same as in the conventional example that the horizontal bar 11 as a reinforcing bar joint on the side of the preceding element 1 protruding from the partition plate 3 is connected to the horizontal bar 12 as a reinforcing bar joint of the reinforcing bar basket 9 on the side of the following element 2. is there.

The partition plate 3 of the present invention is provided with flange plates 7 oriented at right angles to both ends of the partition plate 3, and the overall shape of the partition plate 3 is H-shaped in section. The width of the partition plate 3, that is, the width of the portion that reaches the web with respect to the frangible plate 7 is equal to the distance between the wall surfaces of the drill holes,
Each of the flange plates 7 is in contact with the wall surface of the drill hole and is parallel to the wall of the drill hole.

As a structure of a joint portion for connecting the rear end of the reinforcing bar basket 4 of the leading element 1 and the front end of the reinforcing bar basket 9 of the trailing element 2, the joint on the trailing element 2 side has a horizontally long rectangular cross section. The box-shaped hollow body 14 is continuous in the direction, and the joint on the side of the preceding element 1 is a locking member 17 inserted into the hollow body 14. Among them, the hollow body 14 from the reinforcing bar basket 4 of the leading element 1 is located on the trailing element 2 side.

The box-shaped hollow body 14 has an internal shape of a rectangular shape having a laterally long cross section similar to the outer shape, and this rectangular cross section forms a vertically elongated void which is continuous in the vertical direction. is there. Then, the hollow body 14 has a slit 15 formed in the longitudinal direction on the side surface on the short side, and a vertical plate-shaped joining plate 13 is provided on the side surface opposite to the side surface on which the slit 15 is formed. The tip ends of a plurality of horizontal bars 12 which are spaced apart are connected to the upper and lower stages of the reinforcing bar basket 9 on the row element 2 side. At this time, each of the end portions of the plurality of horizontal streaks 12 has a tubular shape at the end of the joining plate 13 and is allowed to be inserted only with this, or the end of the joining plate 13 is divided into two and the It is conceivable to join them by overlapping and welding. Further, the joint plate 13 has a slit 19 in order to release the strain generated by the welding of the horizontal streaks 12. On the other hand, it is also conceivable to directly join the horizontal streaks 12 to the hollow body 14 without the joining plate 13.

On the other hand, the horizontal streak 11 on the side of the leading element 1 is connected to the joint by projecting its tip from the partition plate 3 to the side of the trailing element 2. The joint on the side of the preceding element 1 is a locking member 17 having a flat plate-shaped enlarged tip portion 16 formed at the tip. The locking member 17 may be either a rod-shaped body or a plate-shaped body, but its rear end is attached to the end of the horizontal line 11 on the side of the preceding element 1 by welding or the like. As shown in FIG. 2, the locking member 17 is provided with slits 20 at the mounting positions of the plurality of horizontal lines 11.
It is assumed that the slit 20 releases the strain caused by welding.

The bulged tip 16 is continuous in the longitudinal direction, and has a left-right width larger than at least the width of the slit 15, and both left and right ends thereof are inside the left and right long sides of the hollow body 14. It is close to each side.
Further, since the front and rear width of the bulged tip portion 16 is thin and has a flat plate shape, when it is inserted into the hollow body 14, it has a void whose position can be adjusted forward and backward. The bulged tip 16 is attached to the locking member 17 separately from the locking member 17, or is attached to the locking member 17.
It is also conceivable to attach it directly to the end of the horizontal streak 11 without. Further, the shape of the bulge tip portion 16 is not limited to a flat plate shape, and it may be considered to be a rectangular body.

The excavation hole on the side of the preceding element 1 is formed, and the reinforcing bar basket 4 provided with the partition plate 3 and the locking member 17 is hung down and concrete 6 is placed therein. And the concrete panel on the side of the preceding element 1 is formed.

After that, the excavation hole 10 on the trailing element 2 side is formed, and the reinforcing bar basket 9 with the hollow body 14 is hung down there. From the opening at the lower end of the hollow body 14, the enlarged tip of the locking member 17 is formed. Insert 16 and slide it through slit 15. Since there is a void in the length range inside the long side of the hollow body 14 before and after the inserted bulge tip 16, it is possible to adjust the position of the bulge tip 16 back and forth within the range of this gap. .

In this way, when the locking member 17 is engaged with the hollow body 14 so that the bulge tip portion 16 can be accommodated in the hollow body 14, the inside of the void existing before and after the bulge tip portion 16 in the hollow body 14 will be described. A non-shrinkable cement-based grout material 18 is injected and filled. The pouring of the grout material 18 is performed by attaching a grout tube 22 for filling grout along the outside of the hollow body 14 as shown in FIG. 4, and connecting the grout tube 22 to the inside of the hollow body 14 at the lower end of the hollow body 14. 22. The bulged tip 16 may have a hole 21 so that the grout material 18 can be easily filled. By grouting the hollow body 14 in this way, the horizontal bars 11 and 12 are connected by a kind of box joint, and the horizontal bars 11 of the reinforcing bar basket 4 on the side of the preceding element 1 and the reinforcing bar basket 9 on the side of the following element 2 are connected. The yield strength of the horizontal muscles is surely transmitted in a state where the axis lines of the horizontal muscles 12 are aligned.

The hollow body 14 and the locking member 17 are provided with the hollow body 14 as a joint on the side of the preceding element 1 and the locking member 17 as a joint on the side of the following element 2 by exchanging the mounting positions thereof. You may do it. Even in this case, the hollow body 14 is located on the trailing element 2 side.

When the locking member 17 and the hollow body 14 are engaged with each other, the tip of the flange plate 7 at the end of the partition plate 3 is located outside thereof, so that the joint portion has an out-of-plane force. When receiving, the bending moment of the partition plate 3, which is H-shaped as a whole, acts, and the flange plate 7 at the end of the partition plate 3 acts as a restraint by restraining this joint portion from the outside.

Further, as a second embodiment, as shown in FIG. 3, the horizontal streak 11 and the horizontal streak 12 have their axes aligned with each other, but the locking member 17
The hollow body 14 and the engaging position may be placed at an eccentric position deviated from this axis. This way, the horizontal streaks 11
When the pulling forces in opposite directions are applied to the horizontal line 12 and the horizontal line 12, moments inward act on the locking member 17, the hollow body 14 and the engaging portion, and the flange plate 7 of the first embodiment is moved. Less restraint is required, and the width of the flange plate 7 can be reduced to reduce the member cost.

The bulged tip 16 of the locking member 17 is formed of a round or rectangular box or pipe extending in the vertical direction, which is used as an injection pipe for the grout material 18. Even in this case, the enlarged tip portion 16 has at least a slit in the left-right width.
The width is larger than the width of 15 and the front and rear width is hollow.
Be able to leave a gap that can be adjusted back and forth when inserted inside. In this way, since the bulged tip 16 made of a box or pipe is used as a grout injection pipe, the bulged tip 16 made of the box or pipe is used when the locking member 17 is engaged with the hollow body 14 or after the engagement. Through this, the inside of the hollow body 14 can be reliably and easily filled with the grout material 18.

[0028]

As described above, in the joint structure for underground continuous walls of the present invention, a partition plate is provided at the reinforcing bar basket end of the preceding element, and a joint projecting from this partition plate and the reinforcing bar basket end of the following element are provided. In the joint structure of underground continuous walls connecting the joints and connecting the horizontal reinforcements, it is possible to reliably transmit the yield strength of the horizontal reinforcements and prevent the splitting fracture. As it is adjustable, construction is easy, and the yield strength of horizontal bars can be reliably transmitted to prevent split fracture.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing a first embodiment of a joint structure for an underground continuous wall of the present invention.

FIG. 2 is a partial vertical cross-sectional side view showing a first embodiment of a joint structure for an underground continuous wall of the present invention.

FIG. 3 is a cross-sectional plan view showing a second embodiment of the joint structure for an underground continuous wall of the present invention.

FIG. 4 is a plan view showing an application example of a hollow body.

FIG. 5 is a cross-sectional plan view showing a conventional example.

FIG. 6 is a vertical sectional side view showing a conventional example.

[Explanation of symbols]

1 ... Leading element 2 ... Trailing element 3 ... Partition plate 4 ... Reinforcing bar basket 5 ... Reinforcing bar joint 5a ... Horizontal bar 5b ... Vertical bar 6 ... Concrete 7 ... Flange plate 8 ... Reinforcing bar joint 8a ... Horizontal bar 9b ... Vertical bar 9 ... Reinforcing bar basket 10… Drilling holes 11 and 12… Horizontal bars 13… Joining plate 14… Hollow body 15… Slit 16… Enlarged tip 17… Locking member 18… Grout material 19… Slit 20… Slit 21… Hole 22… Grout pipe 23 ... rubber plate

Front page continuation (72) Inventor Kazuo Suzuki 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) Reference JP-A-63-176520 (JP, A) JP-A-62-280414 (JP, A) JP-A-63-197714 (JP, A) JP-A-4-353115 (JP, A) Actually developed JP-A-58-176128 (JP, U)

Claims (2)

(57) [Claims] 1. A partition plate is provided at the reinforcing bar basket end of the preceding element, and a joint projecting from this partition plate is connected to a joint at the reinforcing bar basket end of the trailing element to connect horizontal bars to each other. In the joint structure, the partition plate has an H-shaped cross-section so that the flange plate acts to restrain the connecting portions of the both joints from the outside, and one joint has the bulged tip portion of the other joint inside. It is a rectangle with a horizontally long cross section that can leave enough space to adjust the position back and forth when inserted,
A box-shaped hollow body having vertical slits formed on the side surface on the short side side and arranged in the vertical direction is arranged on the side of the trailing element with respect to the partition plate, and there is a vertical gap on the side surface opposite to the vertical slit. The horizontal joints shall be installed so that the other joint is composed of a locking member having a square or flat bulging tip at the tip and connected to the rear ends of the horizontal ribs with a vertical gap. Insert the locking member into the void through a vertical slit, fill the cement-based grout material before and after that, and the axis of the horizontal bar of the reinforcing bar basket on the leading element side and the horizontal bar of the reinforcing bar basket on the trailing element side is Joining structure of underground continuous walls characterized by joining in a matched state. 2. The joint structure for a continuous underground wall according to claim 1, wherein the enlarging tip of the locking member is composed of a box continuous in the vertical direction, and the box is a grout injection pipe.